Marek Raganowicz and Marcin Tomaszewski, both from Poland, have established a major new route on Great Trango in the Karakoram mountains, Pakistan. Their 46-pitch route, called Bushido, ascends the 2000m north-west face of the mountain.

The two climbers topped out on or near the west summit of Great Trango and then abseiled back down their line of ascent.

US climber David Allfrey was initially included in the project, but he withdrew 10 days before departure because of safety fears following the Nanga Parbat massacre. He wrote on his blog that being American was a factor in his decision - the Pakistan Taliban said that the massacre was in response to US drone attacks.

For Raganowicz and Tomaszewski, Allfrey's withdrawal meant that they would each have to carry a greater share of the "big wall" workload. Recognising that they would move more slowly on the wall, they cut their travel and rest time to a minimum and took extra food on the climb.

Bushido follows a system of characteristic red cracks and corners. It starts to the right of the 1999 Russian Route, then crosses the 2007 Belyaev-Loginov-Kommissarov-Mikhalicyn route and goes up the headwall to join the Azeem Ridge climbed by Kelly Cordes and Josh Wharton in 2004.

Raganowicz and Tomaszewski reached Trango base camp on 29 July and spent the next few days ferrying loads to the base camp and fixing the first 8 pitches of the climb. On 3 August they hauled their gear up to Camp 1 on the wall. They set off up the wall from Camp I the following day, climbing "capsule" style with a portaledge, and reached the top on 19 August.

The route involved difficulties of up to VII+ and A4, with a total of 21 belay bolts and 8 rivets.

Snowfalls during the second half of the climb provided a supply of water. But low temperatures and a storm added to the difficulties on the final day of climbing.

The relationship between the top pitches of Bushido and the Azeem Ridge route climbed by Cordes and Wharton isn't quite clear. The ridge is at that point about 100m wide, according to Marek Raganowicz. He says "you can get lost up there."

Raganowicz and Tomaszewski believe that three pitches (their pitches 38-40) were definitely shared with the earlier route. Cordes and Wharton climbed the Azeem Ridge in a very lightweight style and didn't carry a bolt kit.

The Polish team didn't add any belay bolts to the Cordes-Wharton route. Marek Raganowicz says that he added two rivets in the offwidth section of the shared pitches, finding that because of the snowstorm he could not climb this section free.

The climbers found a number of other bolts on the upper ridge. Marek Raganowicz says they didn't place any bolts in this part of the route themselves (the in situ bolts are included on their topo).

The pair say they "climbed on the summit ridge to the highest possible point" but didn't continue to the main summit of Great Trango.

Marcin Tomaszewski reached the top of the route at night in a snowstorm. The high point (see the topo) seems to have been on or close to the point sometimes referred to as the west summit, which stands at the end of a crenellated ridge culminating in the slightly higher southwest summit (c 6250m). The main summit of Great Trango (6286m) lies further to the northeast.

Kelly Cordes and Josh Wharton finished their 2004 ascent of the Azeem Ridge at the southwest summit (some sources treat the 'west summit' and 'southwest summit' as alternative names for this summit; others refer to the lower point at the western end of the summit ridge as the 'west summit' ). They then descended via a hanging glacier to the north-west.

Raganowicz and Tomaszewski say that their abseil descent to the portaledge at Camp 4 was one of the biggest challenges of their mountain career. The ropes were completely frozen and stiff and the gear was covered in snow and hail. They descended to Camp 3, on the terraces beneath the headwall, on 20 August and reached their base camp the following day.

During the course of the whole trip, including travel from Europe, they had just one rest day, spent on the wall.

The name of the route, Bushido, is a Japanese word for the samurai way of life.